annotate dsp/rateconversion/Decimator.h @ 321:f1e6be2de9a5

A threshold (delta) is added in the peak picking parameters structure (PPickParams). It is used as an offset when computing the smoothed detection function. A constructor for the structure PPickParams is also added to set the parameters to 0 when a structure instance is created. Hence programmes using the peak picking parameter structure and which do not set the delta parameter (e.g. QM Vamp note onset detector) won't be affected by the modifications.

Functions modified:
- dsp/onsets/PeakPicking.cpp
- dsp/onsets/PeakPicking.h
- dsp/signalconditioning/DFProcess.cpp
- dsp/signalconditioning/DFProcess.h

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
/*
    QM DSP Library

    Centre for Digital Music, Queen Mary, University of London.
    This file 2005-2006 Christian Landone.

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef DECIMATOR_H
#define DECIMATOR_H

class Decimator  
{
public:
    void process( const double* src, double* dst );
    void process( const float* src, float* dst );

    /**
     * Construct a Decimator to operate on input blocks of length
     * inLength, with decimation factor decFactor.  inLength should be
     * a multiple of decFactor.  Output blocks will be of length
     * inLength / decFactor.
     *
     * decFactor must be a power of two.  The highest supported factor
     * is obtained through getHighestSupportedFactor(); for higher
     * factors, you will need to chain more than one decimator.
     */
    Decimator( unsigned int inLength, unsigned int decFactor );
    virtual ~Decimator();

    int getFactor() const { return m_decFactor; }
    static int getHighestSupportedFactor() { return 8; }

private:
    void resetFilter();
    void deInitialise();
    void initialise( unsigned int inLength, unsigned int decFactor );
    void doAntiAlias( const double* src, double* dst, unsigned int length );
    void doAntiAlias( const float* src, double* dst, unsigned int length );

    unsigned int m_inputLength;
    unsigned int m_outputLength;
    unsigned int m_decFactor;

    double Input;
    double Output ;

    double o1,o2,o3,o4,o5,o6,o7;

    double a[ 9 ];
    double b[ 9 ];
	
    double* decBuffer;
};

#endif //